Patents by Inventor Rahim Tafazolli
Rahim Tafazolli has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11606166Abstract: Apparatus and methods are disclosed for transmitting and receiving data in a wireless communication network. Apparatus for transmitting data in a wireless communication network comprises a real modulation branch for modulating a first segment of a bit sequence to obtain a real modulated signal, a complex modulation branch for modulating a second segment of the bit sequence to obtain a complex modulated signal, a signal dividing unit configured to divide the bit sequence into a plurality of alternating first segments and second segments, and to send the first segments and the second segments to the real modulation branch and the complex modulation branch respectively, and a transmitter configured to transmit the real and complex modulated signals. Apparatus and methods are also disclosed for demultiplexing a plurality of data streams, using wide linear zero forcing with successive interference cancellation.Type: GrantFiled: July 7, 2017Date of Patent: March 14, 2023Assignee: University of SurreyInventors: Juan Carlos De Luna Ducoing, Na Yi, Yi Ma, Rahim Tafazolli
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Patent number: 11569579Abstract: A wireless data transmission apparatus is disclosed, comprising one or more antennas for transmitting data as polarised electromagnetic radiation, and polarisation control means for controlling an axial ratio and a tilt angle of the polarised electromagnetic radiation such that the axial ratio and tilt angle conveys information about the data being transmitted. A corresponding wireless data receiving apparatus is also disclosed. In some embodiments, the one or more antennas comprises a patch antenna, and the polarisation means may comprise a mechanism for varying an electrical length of the angled slot. By utilising the tilt angle and axial ratio of polarised electromagnetic radiation to convey information to the receiver, the spectral efficiency of the system can be increased. A further increase in spectral efficiency may be obtained by using the polarisation control means to modulate first and second carrier waves, and transmitting different data on the first and second carrier waves.Type: GrantFiled: July 25, 2019Date of Patent: January 31, 2023Assignee: University of SurreyInventors: Pei Xiao, Timothy Brown, James Kelly, Yasin Kabiri Isfahani, Rahim Tafazolli
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Publication number: 20220399922Abstract: A method and apparatus for transmitting a wireless signal using a beamforming apparatus having a plurality of antennas is disclosed. The technique comprises: generating a first RF signal; and transmitting, using the plurality of antennas, a corresponding plurality of output RF signals to form the transmitted wireless signal; wherein transmitting the plurality of output RF signals comprises, for each antenna: splitting the first RF signal into a pair of second RF signals; shifting a respective phase of each of the pair of second RF signals; adding the phase shifted pair of second RF signals to form a third RF signal; and transmitting, using the antenna, the third RF signal as the corresponding output RF signal for the antenna.Type: ApplicationFiled: September 10, 2020Publication date: December 15, 2022Inventors: Sohail Payami, Konstantinos Nikitopoulos, Rahim Tafazolli
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Publication number: 20210167508Abstract: A wireless data transmission apparatus is disclosed, comprising one or more antennas for transmitting data as polarised electromagnetic radiation, and polarisation control means for controlling an axial ratio and a tilt angle of the polarised electromagnetic radiation such that the axial ratio and tilt angle conveys information about the data being transmitted. A corresponding wireless data receiving apparatus is also disclosed. In some embodiments, the one or more antennas comprises a patch antenna, and the polarisation means may comprise a mechanism for varying an electrical length of the angled slot. By utilising the tilt angle and axial ratio of polarised electromagnetic radiation to convey information to the receiver, the spectral efficiency of the system can be increased. A further increase in spectral efficiency may be obtained by using the polarisation control means to modulate first and second carrier waves, and transmitting different data on the first and second carrier waves.Type: ApplicationFiled: July 25, 2019Publication date: June 3, 2021Applicant: University of SurreyInventors: Pei XIAO, Timothy BROWN, James KELLY, Yasin KABIRI ISFAHANI, Rahim TAFAZOLLI
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Publication number: 20200186275Abstract: Apparatus and methods are disclosed for transmitting and receiving data in a wireless communication network. Apparatus for transmitting data in a wireless communication network comprises a real modulation branch for modulating a first segment of a bit sequence to obtain a real modulated signal, a complex modulation branch for modulating a second segment of the bit sequence to obtain a complex modulated signal, a signal dividing unit configured to divide the bit sequence into a plurality of alternating first segments and second segments, and to send the first segments and the second segments to the real modulation branch and the complex modulation branch respectively, and a transmitter configured to transmit the real and complex modulated signals. Apparatus and methods are also disclosed for demultiplexing a plurality of data streams, using wide linear zero forcing with successive interference cancellation.Type: ApplicationFiled: July 7, 2017Publication date: June 11, 2020Applicant: University of SurreyInventors: Juan Carlos De Luna DUCOING, Na Yi, Yi MA, Rahim TAFAZOLLI
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Publication number: 20200177302Abstract: Apparatus and methods for performing symbol detection on a plurality of mutually interfering information streams transmitted in a wireless communication system are disclosed. The apparatus comprises a detector configured to receive an input signal comprising a plurality of mutually interfering information streams, and to detect a transmitted symbol for one of the plurality of mutually interfering information streams by searching for a vector solution to an optimization problem, and a detection evaluation module configured to classify the detected symbol as reliable or unreliable, and/or to determine whether current system conditions permit reliable symbol detection and to take a predetermined action to improve the detection reliability according to a result of the determination. In some embodiments a decoding algorithm is then applied to the plurality of detected symbols to recover information from said one of the mutually interfering information streams.Type: ApplicationFiled: August 9, 2018Publication date: June 4, 2020Applicant: University of SurreyInventors: Konstantinos NIKITOPOULOS, Rahim TAFAZOLLI, Christopher HUSMANN
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Patent number: 10374841Abstract: Apparatus and methods for finding a vector solution to a tree search problem are disclosed. In some embodiments, the apparatus and methods can be used for sphere decoding. The tree search is performed by: obtaining a tree graph; identifying a plurality of nodes in the tree graph that are likely to be part of the solution to the tree graph; partitioning the tree graph into a plurality of sub-trees, each sub-tree including one or more of the identified nodes; processing the plurality of sub-trees in parallel by allocating one or more of the processing elements to each of the sub-trees; and determining the solution based on results of the sub-tree processing.Type: GrantFiled: June 7, 2016Date of Patent: August 6, 2019Assignee: UNIVERSITY OF SURREYInventors: Konstantinos Nikitopoulos, Rahim Tafazolli
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Patent number: 10257678Abstract: Data discovery for sensor data in an M2M network uses probabilistic models, such as Gaussian Mixing Models (GMMs) to represent attributes of the sensor data. The parameters of the probabilistic models can be provided to a discovery server (DS) that respond to queries concerning the sensor data. Since the parameters are compressed compared to the attributes of the sensor data itself, this can simplify the distribution of discovery data. A hierarchical arrangement of discovery servers can also be used with multiple levels of discovery servers where higher level discovery servers using more generic probabilistic models.Type: GrantFiled: May 20, 2015Date of Patent: April 9, 2019Assignee: Convida Wireless, LLCInventors: Seyed Amir Hoseinitabatabaei, Payam Barnaghi, Lijun Dong, Chonggang Wang, Rahim Tafazolli
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Publication number: 20180176049Abstract: Apparatus and methods for finding a vector solution to a tree search problem are disclosed. In some embodiments, the apparatus and methods can be used for sphere decoding. The tree search is performed by: obtaining a tree graph; identifying a plurality of nodes in the tree graph that are likely to be part of the solution to the tree graph; partitioning the tree graph into a plurality of sub-trees, each sub-tree including one or more of the identified nodes; processing the plurality of sub-trees in parallel by allocating one or more of the processing elements to each of the sub-trees; and determining the solution based on results of the sub-tree processing.Type: ApplicationFiled: June 7, 2016Publication date: June 21, 2018Inventors: Konstantinos NIKITOPOULOS, Rahim TAFAZOLLI
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Patent number: 9706362Abstract: A method of determining the location of a device on the body of a user carrying it, comprising determining a mathematical representation of a transformation between a device reference frame and an earth reference frame at the device; receiving information from a sensor arrangement of the device capable of measuring device movement while the user is walking, and transforming information from the sensor arrangement, using said mathematical representation, into the earth reference frame at the device; and performing statistical analysis on at least one component of the information from the sensor arrangement obtained in the transformation to identify one or more features corresponding to a specific location of the device. Also provided is a method of determining the orientation of a user's body relative to a reference frame, using a device carried by a user.Type: GrantFiled: April 10, 2013Date of Patent: July 11, 2017Assignee: University of SurreyInventors: Seyed Hoseinitabatabaei, Alexander Gluhak, Rahim Tafazolli
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Publication number: 20170094592Abstract: Data discovery for sensor data in an M2M network uses probabilistic models, such as Gaussian Mixing Models (GMMs) to represent attributes of the sensor data. The parameters of the probabilistic models can be provided to a discovery server (DS) that respond to queries concerning the sensor data. Since the parameters are compressed compared to the attributes of the sensor data itself, this can simplify the distribution of discovery data. A hierarchical arrangement of discovery servers can also be used with multiple levels of discovery servers where higher level discovery servers using more generic probabilistic models.Type: ApplicationFiled: May 20, 2015Publication date: March 30, 2017Inventors: Seyed Amir Hoseini TABATABAEI, Payam BARNAGHI, Lijun DONG, Chonggang WANG, Rahim TAFAZOLLI
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Publication number: 20150072625Abstract: A source detection system for detecting wireless communication signals, the system comprising: receiving means for receiving a signal; and processing means arranged to filter the signal to separate it into a plurality of frequency components, determine an energy content for each of the frequency components, calculate a measure of the difference between the energy contents of respective frequency components, and make a determination, from said measure, whether the signal has been transmitted from a source.Type: ApplicationFiled: April 4, 2012Publication date: March 12, 2015Applicant: THE UNIVERSITY OF SURREYInventors: Parisa Cheraghi, Yi Ma, Rahim Tafazolli
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Publication number: 20150065164Abstract: A method of determining the location of a device on the body of a user carrying it, comprising determining a mathematical representation of a transformation between a device reference frame and an earth reference frame at the device; receiving information from a sensor arrangement of the device capable of measuring device movement while the user is walking, and transforming information from the sensor arrangement, using said mathematical representation, into the earth reference frame at the device; and performing statistical analysis on at least one component of the information from the sensor arrangement obtained in the transformation to identify one or more features corresponding to a specific location of the device. Also provided is a method of determining the orientation of a user's body relative to a reference frame, using a device carried by a user.Type: ApplicationFiled: April 10, 2013Publication date: March 5, 2015Inventors: Seyed Hoseinitabatabaei, Alexander Gluhak, Rahim Tafazolli
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Patent number: 7787412Abstract: A method of obtaining a relative indicator for use in scheduling uplink transmissions from a plurality of source user equipments to a base station is disclosed. The relative indicator indicates the status of a user equipment in comparison to the status of the other user equipments, therefore allowing a user equipment to make more efficient scheduling decisions. The method comprises the steps of determining, for each user equipment, a first indicator which is indicative of a status of that user equipment, determining at least one second indicator from the first indicators obtained for all user equipments and broadcasting the or each second indicator to all user equipments. In this way, a significant reduction the downlink signaling load can be achieved.Type: GrantFiled: August 31, 2005Date of Patent: August 31, 2010Assignee: Fujistu LimitedInventors: Sunil Keshvaji Vadgama, Rahim Tafazolli
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Patent number: 7707278Abstract: A reconfiguration management architecture for a mobile communications system which includes a network and at least one software-definable terminal comprises a configuration management part (10) within the or each terminal and a configuration control part (20). The configuration management part (10) implements a proposed configuration to reconfigure the terminal provided the configuration control part (20) validates the proposed configuration.Type: GrantFiled: November 20, 2001Date of Patent: April 27, 2010Assignee: University of SurreyInventors: Rahim Tafazolli, Klaus Moessner, Seiamak Vahid
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Patent number: 7231216Abstract: A mobile station positioning method for a cellular communications system includes evaluating an initial position estimate of a target mobile station having an initial area of uncertainty, evaluating a position estimate of a further mobile station of the system, estimating distance between the target and further mobile stations and using the position and distance estimates to evaluate a new position estimate of the target mobile station having a reduced area of uncertainty. Bi-circular and tri-circular methods are described.Type: GrantFiled: December 5, 2001Date of Patent: June 12, 2007Assignee: University of SurreyInventors: Rahim Tafazolli, Shahram Ghaheri-Niri, Jung Houn Yap
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Publication number: 20060253464Abstract: A method for determining the optimum allocation of resources in a mobile telecommunication network. The method includes the step of calculating a fitness parameter for each service class where the fitness parameter is dependent on the quality of service index QoSi, the dynamic queue length q1, and the frequency of resources f1, for each service class.Type: ApplicationFiled: January 23, 2004Publication date: November 9, 2006Inventors: Shyamalie Thilakawardana, Rahim Tafazolli
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Publication number: 20060067275Abstract: A method for estimating cell coverage in a mobile telecommunications network. The method includes the steps of receiving signal quality and position information from the users of the network and using the information to calculate a coverage map. Update information is also received to update the coverage map. The estimated cell coverage can be used in radio resource allocation methods.Type: ApplicationFiled: September 30, 2004Publication date: March 30, 2006Applicant: University of SurreyInventors: Xinjie Yang, Rahim Tafazolli
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Publication number: 20060056346Abstract: A method of obtaining a relative indicator for use in scheduling uplink transmissions from a plurality of source user equipments to a base station is disclosed. The relative indicator indicates the status of a user equipment in comparison to the status of the other user equipments, therefore allowing a user equipment to make more efficient scheduling decisions. The method comprises the steps of determining, for each user equipment, a first indicator which is indicative of a status of that user equipment, determining at least one second indicator from the first indicators obtained for all user equipments and broadcasting the or each second indicator to all user equipments. In this way, a significant reduction the downlink signalling load can be achieved.Type: ApplicationFiled: August 31, 2005Publication date: March 16, 2006Inventors: Sunil Vadgama, Rahim Tafazolli
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Publication number: 20050075111Abstract: A mobile station positioning method for a cellular communications system includes evaluating an initial position estimate of a target mobile station having an initial area of uncertainty, evaluating a position estimate of a further mobile station of the system, estimating distance between the target and further mobile stations and using the position and distance estimates to evaluate a new position estimate of the target mobile station having a reduced area of uncertainty. Bi-circular and tri-circular methods are described.Type: ApplicationFiled: December 5, 2001Publication date: April 7, 2005Applicant: University of SurreyInventors: Rahim Tafazolli, Shahram Ghaheri-Niri, Jung Yap